@inproceedings{BehbahaniRibleMoulinecetal.2015,
  author    = {Behbahani, Mehdi and Rible, Sebastian and Moulinec, Charles and Fournier, Yvan and Nicolai, Mike and Crosetto, Paolo},
  title     = {Simulation of the FDA Centrifugal Blood Pump Using High Performance Computing},
  series = {World Academy of Science, Engineering and Technology International Journal of Mechanical and Mechatronics Engineering},
  volume    = {9},
  booktitle = {World Academy of Science, Engineering and Technology International Journal of Mechanical and Mechatronics Engineering},
  number    = {5},
  year      = {2015},
  language  = {en}
}
@article{KoppSchmeetsGosauetal.2019,
  author    = {Kopp, Alexander and Schmeets, Ralf and Gosau, Martin and Friedrich, Reinhard E. and Fuest, Sandra and Behbahani, Mehdi and Barbeck, Mike and Rutkowski, Rico and Burg, Simon and Kluwe, Lan and Henningsen, Anders},
  title     = {Production and Characterization of Porous Fibroin Scaffolds for Regenerative Medical Application},
  series = {In Vivo},
  volume    = {33},
  journal   = {In Vivo},
  number    = {3},
  issn      = {1791-7549},
  doi       = {10.21873/invivo.11536},
  pages     = {757 -- 762},
  year      = {2019},
  language  = {en}
}
@phdthesis{Behbahani2011,
  author    = {Behbahani, Mehdi},
  title     = {Modeling and Simulation of Shear-Dependent Platelet Reactions in Blood Vessels and Blood-Contacting Medical Devices},
  publisher = {Verlag Dr. Hut},
  address   = {M{\"u}nchen},
  isbn      = {978-3-8439-0134-5},
  year      = {2011},
  language  = {en}
}
@inproceedings{MandekarJentschLutzetal.2021,
  author    = {Mandekar, Swati and Jentsch, Lina and Lutz, Kai and Behbahani, Mehdi and Melnykowycz, Mark},
  title     = {Earable design analysis for sleep EEG measurements},
  series = {UbiComp '21},
  booktitle = {UbiComp '21},
  doi       = {10.1145/3460418.3479328},
  pages     = {171 -- 175},
  year      = {2021},
  abstract  = {Conventional EEG devices cannot be used in everyday life and hence, past decade research has been focused on Ear-EEG for mobile, at-home monitoring for various applications ranging from emotion detection to sleep monitoring. As the area available for electrode contact in the ear is limited, the electrode size and location play a vital role for an Ear-EEG system. In this investigation, we present a quantitative study of ear-electrodes with two electrode sizes at different locations in a wet and dry configuration. Electrode impedance scales inversely with size and ranges from 450 kΩ to 1.29 MΩ for dry and from 22 kΩ to 42 kΩ for wet contact at 10 Hz. For any size, the location in the ear canal with the lowest impedance is ELE (Left Ear Superior), presumably due to increased contact pressure caused by the outer-ear anatomy. The results can be used to optimize signal pickup and SNR for specific applications. We demonstrate this by recording sleep spindles during sleep onset with high quality (5.27 μVrms).},
  language  = {en}
}
@article{MalinowskiFournierHorbachetal.2022,
  author    = {Malinowski, Daniel and Fournier, Yvan and Horbach, Andreas and Frick, Michael and Magliani, Mirko and Kalverkamp, Sebastian and Hildinger, Martin and Spillner, Jan and Behbahani, Mehdi and Hima, Flutura},
  title     = {Computational fluid dynamics analysis of endoluminal aortic perfusion},
  series = {Perfusion},
  volume    = {0},
  journal   = {Perfusion},
  number    = {0},
  publisher = {Sage},
  address   = {London},
  issn      = {1477-111X},
  doi       = {10.1177/02676591221099809},
  pages     = {1 -- 8},
  year      = {2022},
  abstract  = {Introduction: In peripheral percutaneous (VA) extracorporeal membrane oxygenation (ECMO) procedures the femoral arteries perfusion route has inherent disadvantages regarding poor upper body perfusion due to watershed. With the advent of new long flexible cannulas an advancement of the tip up to the ascending aorta has become feasible. To investigate the impact of such long endoluminal cannulas on upper body perfusion, a Computational Fluid Dynamics (CFD) study was performed considering different support levels and three cannula positions. Methods: An idealized literature-based- and a real patient proximal aortic geometry including an endoluminal cannula were constructed. The blood flow was considered continuous. Oxygen saturation was set to 80\% for the blood coming from the heart and to 100\% for the blood leaving the cannula. 50\% and 90\% venoarterial support levels from the total blood flow rate of 6 l/min were investigated for three different positions of the cannula in the aortic arch. Results: For both geometries, the placement of the cannula in the ascending aorta led to a superior oxygenation of all aortic blood vessels except for the left coronary artery. Cannula placements at the aortic arch and descending aorta could support supra-aortic arteries, but not the coronary arteries. All positions were able to support all branches with saturated blood at 90\% flow volume. Conclusions: In accordance with clinical observations CFD analysis reveals, that retrograde advancement of a long endoluminal cannula can considerably improve the oxygenation of the upper body and lead to oxygen saturation distributions similar to those of a central cannulation.},
  language  = {en}
}
@article{LenzKahmannBehbahanietal.2022,
  author    = {Lenz, Maximilian and Kahmann, Stephanie Lucina and Behbahani, Mehdi and Pennig, Lenhard and Hackl, Michael and Leschinger, Tim and M{\"u}ller, Lars Peter and Wegmann, Kilian},
  title     = {Influence of rotator cuff preload on fracture configuration in proximal humerus fractures: a proof of concept for fracture simulation},
  series = {Archives of Orthopaedic and Trauma Surgery},
  journal   = {Archives of Orthopaedic and Trauma Surgery},
  publisher = {Springer},
  address   = {Berlin, Heidelberg},
  issn      = {1434-3916},
  doi       = {10.1007/s00402-022-04471-9},
  year      = {2022},
  abstract  = {Introduction In regard of surgical training, the reproducible simulation of life-like proximal humerus fractures in human cadaveric specimens is desirable. The aim of the present study was to develop a technique that allows simulation of realistic proximal humerus fractures and to analyse the influence of rotator cuff preload on the generated lesions in regards of fracture configuration. Materials and methods Ten cadaveric specimens (6 left, 4 right) were fractured using a custom-made drop-test bench, in two groups. Five specimens were fractured without rotator cuff preload, while the other five were fractured with the tendons of the rotator cuff preloaded with 2 kg each. The humeral shaft and the shortened scapula were potted. The humerus was positioned at 90° of abduction and 10° of internal rotation to simulate a fall on the elevated arm. In two specimens of each group, the emergence of the fractures was documented with high-speed video imaging. Pre-fracture radiographs were taken to evaluate the deltoid-tuberosity index as a measure of bone density. Post-fracture X-rays and CT scans were performed to define the exact fracture configurations. Neer's classification was used to analyse the fractures. Results In all ten cadaveric specimens life-like proximal humerus fractures were achieved. Two III-part and three IV-part fractures resulted in each group. The preloading of the rotator cuff muscles had no further influence on the fracture configuration. High-speed videos of the fracture simulation revealed identical fracture mechanisms for both groups. We observed a two-step fracture mechanism, with initial impaction of the head segment against the glenoid followed by fracturing of the head and the tuberosities and then with further impaction of the shaft against the acromion, which lead to separation of the tuberosities. Conclusion A high energetic axial impulse can reliably induce realistic proximal humerus fractures in cadaveric specimens. The preload of the rotator cuff muscles had no influence on initial fracture configuration. Therefore, fracture simulation in the proximal humerus is less elaborate. Using the presented technique, pre-fractured specimens are available for real-life surgical education.},
  language  = {en}
}
@article{ChloeMalyaranCraveiroetal.2022,
  author    = {Chlo{\´e}, Radermacher and Malyaran, Hanna and Craveiro, Rogerio Bastos and Peglow, Sarah and Behbahani, Mehdi and Pufe, Thomas and Wolf, Michael and Neuss, Sabine},
  title     = {Mechanical loading on cementoblasts: a mini review},
  series = {Osteologie},
  volume    = {31},
  journal   = {Osteologie},
  number    = {2},
  publisher = {Thieme},
  address   = {Stuttgart},
  issn      = {1019-1291},
  doi       = {10.1055/a-1826-0777},
  pages     = {111 -- 118},
  year      = {2022},
  abstract  = {Orthodontic treatments are concomitant with mechanical forces and thereby cause teeth movements. The applied forces are transmitted to the tooth root and the periodontal ligaments which is compressed on one side and tensed up on the other side. Indeed, strong forces can lead to tooth root resorption and the crown-to-tooth ratio is reduced with the potential for significant clinical impact. The cementum, which covers the tooth root, is a thin mineralized tissue of the periodontium that connects the periodontal ligament with the tooth and is build up by cementoblasts. The impact of tension and compression on these cells is investigated in several in vivo and in vitro studies demonstrating differences in protein expression and signaling pathways. In summary, osteogenic marker changes indicate that cyclic tensile forces support whereas static tension inhibits cementogenesis. Furthermore, cementogenesis experiences the same protein expression changes in static conditions as static tension, but cyclic compression leads to the exact opposite of cyclic tension. Consistent with marker expression changes, the singaling pathways of Wnt/ß-catenin and RANKL/OPG show that tissue compression leads to cementum degradation and tension forces to cementogenesis. However, the cementum, and in particular its cementoblasts, remain a research area which should be explored in more detail to understand the underlying mechanism of bone resorption and remodeling after orthodontic treatments.},
  language  = {en}
}
@article{KoppSchunckGosauetal.2020,
  author    = {Kopp, Alexander and Schunck, Laura and Gosau, Martin and Smeets, Ralf and Burg, Simon and Fuest, Sandra and Kr{\"o}ger, Nadja and Zinser, Max and Krohn, Sebastian and Behbahani, Mehdi and K{\"o}pf, Marius and Lauts, Lisa and Rutkowski, Rico},
  title     = {Influence of the casting concentration on the mechanical and optical properties of Fa/CaCl2-derived silk fibroin membranes},
  series = {International Journal of Molecular Sciences},
  volume    = {21},
  journal   = {International Journal of Molecular Sciences},
  number    = {18 art. no. 6704},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1422-0067},
  doi       = {10.3390/ijms21186704},
  year      = {2020},
  abstract  = {In this study, we describe the manufacturing and characterization of silk fibroin membranes derived from the silkworm Bombyx mori. To date, the dissolution process used in this study has only been researched to a limited extent, although it entails various potential advantages, such as reduced expenses and the absence of toxic chemicals in comparison to other conventional techniques. Therefore, the aim of this study was to determine the influence of different fibroin concentrations on the process output and resulting membrane properties. Casted membranes were thus characterized with regard to their mechanical, structural and optical assets via tensile testing, SEM, light microscopy and spectrophotometry. Cytotoxicity was evaluated using BrdU, XTT, and LDH assays, followed by live-dead staining. The formic acid (FA) dissolution method was proven to be suitable for the manufacturing of transparent and mechanically stable membranes. The fibroin concentration affects both thickness and transparency of the membranes. The membranes did not exhibit any signs of cytotoxicity. When compared to other current scientific and technical benchmarks, the manufactured membranes displayed promising potential for various biomedical applications. Further research is nevertheless necessary to improve reproducible manufacturing, including a more uniform thickness, less impurity and physiological pH within the membranes.},
  language  = {en}
}
@article{BrockhausBehbahaniMurisetal.2021,
  author    = {Brockhaus, Moritz K. and Behbahani, Mehdi and Muris, Farina and Jansen, Sebastian V. and Schmitz- Rode, Thomas and Steinseifer, Ulrich and Clauser, Johanna C.},
  title     = {In vitro thrombogenicity testing of pulsatile mechanical circulatory support systems: Design and proof-of-concept},
  series = {Artificial Organs},
  volume    = {45},
  journal   = {Artificial Organs},
  number    = {12},
  publisher = {Wiley},
  address   = {Weinheim},
  issn      = {1525-1594},
  doi       = {10.1111/aor.14046},
  pages     = {1513 -- 1521},
  year      = {2021},
  abstract  = {Thrombogenic complications are a main issue in mechanical circulatory support (MCS). There is no validated in vitro method available to quantitatively assess the thrombogenic performance of pulsatile MCS devices under realistic hemodynamic conditions. The aim of this study is to propose a method to evaluate the thrombogenic potential of new designs without the use of complex in-vivo trials. This study presents a novel in vitro method for reproducible thrombogenicity testing of pulsatile MCS systems using low molecular weight heparinized porcine blood. Blood parameters are continuously measured with full blood thromboelastometry (ROTEM; EXTEM, FIBTEM and a custom-made analysis HEPNATEM). Thrombus formation is optically observed after four hours of testing. The results of three experiments are presented each with two parallel loops. The area of thrombus formation inside the MCS device was reproducible. The implantation of a filter inside the loop catches embolizing thrombi without a measurable increase of platelet activation, allowing conclusions of the place of origin of thrombi inside the device. EXTEM and FIBTEM parameters such as clotting velocity (α) and maximum clot firmness (MCF) show a total decrease by around 6\% with a characteristic kink after 180 minutes. HEPNATEM α and MCF rise within the first 180 minutes indicate a continuously increasing activation level of coagulation. After 180 minutes, the consumption of clotting factors prevails, resulting in a decrease of α and MCF. With the designed mock loop and the presented protocol we are able to identify thrombogenic hot spots inside a pulsatile pump and characterize their thrombogenic potential.},
  language  = {en}
}
@article{MandekarHollandThielenetal.2022,
  author    = {Mandekar, Swati and Holland, Abigail and Thielen, Moritz and Behbahani, Mehdi and Melnykowycz, Mark},
  title     = {Advancing towards Ubiquitous EEG, Correlation of In-Ear EEG with Forehead EEG},
  series = {Sensors},
  volume    = {22},
  journal   = {Sensors},
  number    = {4},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1424-8220},
  doi       = {10.3390/s22041568},
  pages     = {1 -- 19},
  year      = {2022},
  abstract  = {Wearable EEG has gained popularity in recent years driven by promising uses outside of clinics and research. The ubiquitous application of continuous EEG requires unobtrusive form-factors that are easily acceptable by the end-users. In this progression, wearable EEG systems have been moving from full scalp to forehead and recently to the ear. The aim of this study is to demonstrate that emerging ear-EEG provides similar impedance and signal properties as established forehead EEG. EEG data using eyes-open and closed alpha paradigm were acquired from ten healthy subjects using generic earpieces fitted with three custom-made electrodes and a forehead electrode (at Fpx) after impedance analysis. Inter-subject variability in in-ear electrode impedance ranged from 20 kΩ to 25 kΩ at 10 Hz. Signal quality was comparable with an SNR of 6 for in-ear and 8 for forehead electrodes. Alpha attenuation was significant during the eyes-open condition in all in-ear electrodes, and it followed the structure of power spectral density plots of forehead electrodes, with the Pearson correlation coefficient of 0.92 between in-ear locations ELE (Left Ear Superior) and ERE (Right Ear Superior) and forehead locations, Fp1 and Fp2, respectively. The results indicate that in-ear EEG is an unobtrusive alternative in terms of impedance, signal properties and information content to established forehead EEG.},
  language  = {en}
}
@inproceedings{SchmitzApandiSpillneretal.2024,
  author    = {Schmitz, Annika and Apandi, Shah Eiman Amzar Shah and Spillner, Jan and Hima, Flutura and Behbahani, Mehdi},
  title     = {Effect of different cannula positions in the pulmonary artery on blood flow and gas exchange using computational fluid dynamics analysis},
  series = {4th YRA MedTech Symposium 2024 : February 1 / 2024 / FH Aachen},
  booktitle = {4th YRA MedTech Symposium 2024 : February 1 / 2024 / FH Aachen},
  editor    = {Digel, Ilya and Staat, Manfred and Trzewik, J{\"u}rgen and Sielemann, Stefanie and Erni, Daniel and Zylka, Waldemar},
  publisher = {Universit{\"a}t Duisburg-Essen},
  address   = {Duisburg},
  organization    = {MedTech Symposium},
  isbn      = {978-3-940402-65-3},
  doi       = {10.17185/duepublico/81475},
  pages     = {29 -- 30},
  year      = {2024},
  abstract  = {Pulmonary arterial cannulation is a common and effective method for percutaneous mechanical circulatory support for concurrent right heart and respiratory failure [1]. However, limited data exists to what effect the positioning of the cannula has on the oxygen perfusion throughout the pulmonary artery (PA). This study aims to evaluate, using computational fluid dynamics (CFD), the effect of different cannula positions in the PA with respect to the oxygenation of the different branching vessels in order for an optimal cannula position to be determined. The four chosen different positions (see Fig. 1) of the cannulas are, in the lower part of the main pulmonary artery (MPA), in the MPA at the junction between the right pulmonary artery (RPA) and the left pulmonary artery (LPA), in the RPA at the first branch of the RPA and in the LPA at the first branch of the LPA.},
  language  = {en}
}
@article{ThiebesKleinZingsheimetal.2022,
  author    = {Thiebes, Anja Lena and Klein, Sarah and Zingsheim, Jonas and M{\"o}ller, Georg H. and G{\"u}rzing, Stefanie and Reddemann, Manuel A. and Behbahani, Mehdi and Cornelissen, Christian G.},
  title     = {Effervescent atomizer as novel cell spray technology to decrease the gas-to-liquid ratio},
  series = {pharmaceutics},
  volume    = {14},
  journal   = {pharmaceutics},
  number    = {11},
  publisher = {MDPI},
  address   = {Basel},
  doi       = {10.3390/pharmaceutics14112421},
  pages     = {Artikel 2421},
  year      = {2022},
  abstract  = {Cell spraying has become a feasible application method for cell therapy and tissue engineering approaches. Different devices have been used with varying success. Often, twin-fluid atomizers are used, which require a high gas velocity for optimal aerosolization characteristics. To decrease the amount and velocity of required air, a custom-made atomizer was designed based on the effervescent principle. Different designs were evaluated regarding spray characteristics and their influence on human adipose-derived mesenchymal stromal cells. The arithmetic mean diameters of the droplets were 15.4-33.5 µm with decreasing diameters for increasing gas-to-liquid ratios. The survival rate was >90\% of the control for the lowest gas-to-liquid ratio. For higher ratios, cell survival decreased to approximately 50\%. Further experiments were performed with the design, which had shown the highest survival rates. After seven days, no significant differences in metabolic activity were observed. The apoptosis rates were not influenced by aerosolization, while high gas-to-liquid ratios caused increased necrosis levels. Tri-lineage differentiation potential into adipocytes, chondrocytes, and osteoblasts was not negatively influenced by aerosolization. Thus, the effervescent aerosolization principle was proven suitable for cell applications requiring reduced amounts of supplied air. This is the first time an effervescent atomizer was used for cell processing.},
  language  = {en}
}
@article{BelavyAlbrachtBruggemannetal.2016,
  author    = {Belavy, Daniel L. and Albracht, Kirsten and Bruggemann, Gert-Peter and Vergroesen, Pieter-Paul A. and Dieen, Jaap H. van},
  title     = {Can exercise positively influence the intervertebral disc?},
  series = {Sports Medicine},
  volume    = {46},
  journal   = {Sports Medicine},
  number    = {4},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {1179-2035},
  doi       = {10.1007/s40279-015-0444-2},
  pages     = {473 -- 485},
  year      = {2016},
  abstract  = {To better understand what kinds of sports and exercise could be beneficial for the intervertebral disc (IVD), we performed a review to synthesise the literature on IVD adaptation with loading and exercise. The state of the literature did not permit a systematic review; therefore, we performed a narrative review. The majority of the available data come from cell or whole-disc loading models and animal exercise models. However, some studies have examined the impact of specific sports on IVD degeneration in humans and acute exercise on disc size. Based on the data available in the literature, loading types that are likely beneficial to the IVD are dynamic, axial, at slow to moderate movement speeds, and of a magnitude experienced in walking and jogging. Static loading, torsional loading, flexion with compression, rapid loading, high-impact loading and explosive tasks are likely detrimental for the IVD. Reduced physical activity and disuse appear to be detrimental for the IVD. We also consider the impact of genetics and the likelihood of a 'critical period' for the effect of exercise in IVD development. The current review summarises the literature to increase awareness amongst exercise, rehabilitation and ergonomic professionals regarding IVD health and provides recommendations on future directions in research.},
  language  = {en}
}
@article{YangKriechbaumerAlbrachtetal.2015,
  author    = {Yang, Peng-Fei and Kriechbaumer, Andreas and Albracht, Kirsten and Sanno, Maximilian and Ganse, Bergita and Koy, Timmo and Shang, Peng and Br{\"u}ggemann, Gert-Peter and M{\"u}ller, Lars Peter and Rittweger, J{\"o}rn},
  title     = {On the relationship between tibia torsional deformation and regional muscle contractions in habitual human exercises in vivo},
  series = {Journal of Biomechanics},
  volume    = {48},
  journal   = {Journal of Biomechanics},
  number    = {3},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0021-9290},
  doi       = {10.1016/j.jbiomech.2014.12.031},
  pages     = {456 -- 464},
  year      = {2015},
  language  = {en}
}
@article{SeynnesBojsenMollerAlbrachtetal.2015,
  author    = {Seynnes, O. R. and Bojsen-Moller, J. and Albracht, Kirsten and Arndt, A. and Cronin, N. J. and Finni, T. and Magnusson, S. P.},
  title     = {Ultrasound-based testing of tendon mechanical properties: a critical evaluation},
  series = {Journal of Applied Physiology},
  volume    = {118},
  journal   = {Journal of Applied Physiology},
  number    = {2},
  issn      = {8750-7587},
  doi       = {10.1152/japplphysiol.00849.2014},
  pages     = {133 -- 141},
  year      = {2015},
  language  = {en}
}
@article{AlbrachtArampatzis2013,
  author    = {Albracht, Kirsten and Arampatzis, Adamantios},
  title     = {Exercise-induced changes in triceps surae tendon stiffness and muscle strength affect running economy in humans},
  series = {European Journal of Applied Physiology},
  volume    = {113},
  journal   = {European Journal of Applied Physiology},
  number    = {6},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {1439-6327},
  doi       = {10.1007/s00421-012-2585-4},
  pages     = {1605 -- 1615},
  year      = {2013},
  language  = {en}
}
@article{KaramanidisAlbrachtBraunsteinetal.2011,
  author    = {Karamanidis, Kiros and Albracht, Kirsten and Braunstein, Bjoern and Catala, Maria Moreno and Goldmann, Jan-Peter and Br{\"u}ggemann, Gert-Peter},
  title     = {Lower leg musculoskeletal geometry and sprint performance},
  series = {Gait and Posture},
  volume    = {34},
  journal   = {Gait and Posture},
  number    = {1},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0966-6362},
  doi       = {10.1016/j.gaitpost.2011.03.009},
  pages     = {138 -- 141},
  year      = {2011},
  abstract  = {The purpose of this study was to investigate whether sprint performance is related to lower leg musculoskeletal geometry within a homogeneous group of highly trained 100-m sprinters. Using a cluster analysis, eighteen male sprinters were divided into two groups based on their personal best (fast: N = 11, 10.30 ± 0.07 s; slow: N = 7, 10.70 ± 0.08 s). Calf muscular fascicle arrangement and Achilles tendon moment arms (calculated by the gradient of tendon excursion versus ankle joint angle) were analyzed for each athlete using ultrasonography. Achilles tendon moment arm, foot and ankle skeletal geometry, fascicle arrangement as well as the ratio of fascicle length to Achilles tendon moment arm showed no significant (p > 0.05) correlation with sprint performance, nor were there any differences in the analyzed musculoskeletal parameters between the fast and slow sprinter group. Our findings provide evidence that differences in sprint ability in world-class athletes are not a result of differences in the geometrical design of the lower leg even when considering both skeletal and muscular components.},
  language  = {en}
}
@article{ArampatzisKaramanidisMademlietal.2009,
  author    = {Arampatzis, Adamantios and Karamanidis, Kiros and Mademli, Lida and Albracht, Kirsten},
  title     = {Plasticity of the human tendon to short and long-term mechanical loading},
  series = {Exercise and Sport Sciences Reviews},
  volume    = {37},
  journal   = {Exercise and Sport Sciences Reviews},
  number    = {2},
  issn      = {1538-3008},
  doi       = {10.1097/JES.0b013e31819c2e1d},
  pages     = {66 -- 72},
  year      = {2009},
  language  = {en}
}
@article{AlbrachtArampatzisBaltzopoulos2008,
  author    = {Albracht, Kirsten and Arampatzis, A. and Baltzopoulos, V.},
  title     = {Assessment of muscle volume and physiological cross-sectional area of the human triceps surae muscle in vivo},
  series = {Journal of Biomechanics},
  volume    = {41},
  journal   = {Journal of Biomechanics},
  issn      = {0021-9290},
  doi       = {10.1016/j.jbiomech.2008.04.020},
  pages     = {2211 -- 2218},
  year      = {2008},
  language  = {en}
}
@article{ArampatzisKaramanidisAlbracht2007,
  author    = {Arampatzis, Adamantios and Karamanidis, Kiros and Albracht, Kirsten},
  title     = {Adaptational responses of the human Achilles tendon by modulation of the applied cyclic strain magnitude},
  series = {Journal of Experimental Biology},
  volume    = {210},
  journal   = {Journal of Experimental Biology},
  number    = {15},
  issn      = {0022-0949},
  doi       = {10.1242/jeb.003814},
  pages     = {2743 -- 2753},
  year      = {2007},
  language  = {en}
}
@article{AlbrachtArampatzis2006,
  author    = {Albracht, Kirsten and Arampatzis, Adamantios},
  title     = {Influence of the mechanical properties of the muscle-tendon unit on force generation in runners with different running economy},
  series = {Biological Cybernetics},
  volume    = {95},
  journal   = {Biological Cybernetics},
  number    = {1},
  issn      = {1432-0770},
  doi       = {10.1007/s00422-006-0070-z},
  pages     = {87 -- 96},
  year      = {2006},
  language  = {en}
}
@inproceedings{GoldmannBraunsteinHeinrichetal.2015,
  author    = {Goldmann, Jan-Peter and Braunstein, Bjoern and Heinrich, Kai and Sanno, Maximilian and St{\"a}udle, Benjamin and Ritzdorf, Wolfgang and Br{\"u}ggemann, Gert-Peter and Albracht, Kirsten},
  title     = {Joint work of the take-off leg during elite high jump},
  series = {Proceedings of the 33th International Conference on Biomechanics in Sports (ISBS)},
  booktitle = {Proceedings of the 33th International Conference on Biomechanics in Sports (ISBS)},
  pages     = {3 S.},
  year      = {2015},
  language  = {en}
}
@inproceedings{DroszezSannoGoldmannetal.2016,
  author    = {Droszez, Anna and Sanno, Maximilian and Goldmann, Jan-Peter and Albracht, Kirsten and Br{\"u}ggemann, Gerd-Peter and Braunstein, Bjoern},
  title     = {Differences between take-off behavior during vertical jumps and two artistic elements},
  series = {34th International Conference of Biomechanics in Sport, Tsukuba, Japan, July 18-22, 2016},
  booktitle = {34th International Conference of Biomechanics in Sport, Tsukuba, Japan, July 18-22, 2016},
  issn      = {1999-4168},
  pages     = {577 -- 580},
  year      = {2016},
  language  = {en}
}
@inproceedings{AbelBoninAlbrachtetal.2010,
  author    = {Abel, Thomas and Bonin, Dominik and Albracht, Kirsten and Zeller, Sebastian and Br{\"u}ggemann, Gert-Peter and Burkett, Brendan and Str{\"u}der, Heiko K.},
  title     = {Kinematic profile of the elite handcyclist},
  series = {28th International Conference on Biomechanics in Sports, Marquette, Michigan, USA, July 19 - 23, 2010},
  booktitle = {28th International Conference on Biomechanics in Sports, Marquette, Michigan, USA, July 19 - 23, 2010},
  issn      = {1999-4168},
  pages     = {140 -- 141},
  year      = {2010},
  language  = {en}
}
@inproceedings{BraunsteinGoldmannAlbrachtetal.2013,
  author    = {Braunstein, Bjoern and Goldmann, Jan-Peter and Albracht, Kirsten and Sanno, Maximilian and Willwacher, Steffen and Heinrich, Kai and Herrmann, Volker and Br{\"u}ggemann, Gert-Peter},
  title     = {Joint specific contribution of mechanical power and work during acceleration and top speed in elite sprinters},
  series = {31 International Conference on Biomechanics in Sports, Taipei, Taiwan, July 07 - July 22, 2013},
  booktitle = {31 International Conference on Biomechanics in Sports, Taipei, Taiwan, July 07 - July 22, 2013},
  issn      = {1999-4168},
  year      = {2013},
  language  = {en}
}
@phdthesis{Albracht2010,
  author    = {Albracht, Kirsten},
  title     = {Influence of mechanical properties of the leg extensor muscletendon units on running economy},
  publisher = {Deutsche Sporthochschule K{\"o}ln},
  address   = {K{\"o}ln},
  pages     = {X, 1221 Bl. : graph. Darst.},
  year      = {2010},
  language  = {en}
}
@inproceedings{KolditzAlbrachtFasseetal.2015,
  author    = {Kolditz, Melanie and Albracht, Kirsten and Fasse, Alessandro and Albin, Thivaharan and Br{\"u}ggemann, Gert-Peter and Abel, Dirk},
  title     = {Evaluation of an industrial robot as a leg press training device},
  series = {XV International Symposium on Computer Simulation in Biomechanics July 9th - 11th 2015, Edinburgh, UK},
  booktitle = {XV International Symposium on Computer Simulation in Biomechanics July 9th - 11th 2015, Edinburgh, UK},
  pages     = {41 -- 42},
  year      = {2015},
  language  = {en}
}
@inproceedings{KolditzAlbinFasseetal.2015,
  author    = {Kolditz, Melanie and Albin, Thivaharan and Fasse, Alessandro and Br{\"u}ggemann, Gert-Peter and Abel, Dirk and Albracht, Kirsten},
  title     = {Simulative Analysis of Joint Loading During Leg Press Exercise for Control Applications},
  series = {IFAC-PapersOnLine},
  volume    = {48},
  booktitle = {IFAC-PapersOnLine},
  number    = {20},
  doi       = {10.1016/j.ifacol.2015.10.179},
  pages     = {435 -- 440},
  year      = {2015},
  language  = {en}
}
@article{ZangeSchopenAlbrachtetal.2017,
  author    = {Zange, Jochen and Schopen, Kathrin and Albracht, Kirsten and Gerlach, Darius A. and Frings-Meuthen, Petra and Maffiuletti, Nicola A. and Bloch, Wilhelm and Rittweger, J{\"o}rn},
  title     = {Using the Hephaistos orthotic device to study countermeasure effectiveness of neuromuscular electrical stimulation and dietary lupin protein supplementation, a randomised controlled trial},
  series = {Plos one},
  volume    = {12},
  journal   = {Plos one},
  number    = {2},
  doi       = {10.1371/journal.pone.0171562},
  year      = {2017},
  language  = {en}
}
@article{WerkhausenAlbrachtCroninetal.2017,
  author    = {Werkhausen, Amelie and Albracht, Kirsten and Cronin, Neil J. and Meier, Rahel and Mojsen-Moeller, Jens and Seynnes, Olivier R.},
  title     = {Modulation of muscle-tendon interaction in the human triceps surae during an energy dissipation task},
  series = {Journal of Experimental Biology},
  volume    = {220},
  journal   = {Journal of Experimental Biology},
  number    = {22},
  issn      = {0022-0949},
  doi       = {10.1242/jeb.164111},
  pages     = {4141 -- 4149},
  year      = {2017},
  language  = {en}
}
@article{RittwegerAlbrachtFluecketal.2018,
  author    = {Rittweger, J{\"o}rn and Albracht, Kirsten and Fl{\"u}ck, Martin and Ruoss, Severin and Brocca, Lorenza and Longa, Emanuela and Moriggi, Manuela and Seynnes, Olivier and Di Giulio, Irene and Tenori, Leonardo and Vignoli, Alessia and Capri, Miriam and Gelfi, Cecilia and Luchinat, Claudio and Franceschi, Claudio and Bottinelli, Roberto and Cerretelli, Paolo and Narici, Marco},
  title     = {Sarcolab pilot study into skeletal muscle's adaptation to longterm spaceflight},
  series = {npj Microgravity},
  volume    = {4},
  journal   = {npj Microgravity},
  number    = {1},
  publisher = {Nature Portfolio},
  issn      = {2373-8065},
  doi       = {10.1038/s41526-018-0052-1},
  pages     = {1 -- 9},
  year      = {2018},
  language  = {en}
}
@inproceedings{RichterBraunsteinStaeudleetal.2018,
  author    = {Richter, Charlotte and Braunstein, Bjoern and St{\"a}udle, Benjamin and Attias, Julia and Suess, Alexander and Weber, T. and Rittweger, Joern and Green, David A. and Albracht, Kirsten},
  title     = {In vivo fascicle length of the gastrocnemius muscle during walking in simulated martian gravity using two different body weight support devices},
  series = {23rd Annual Congress of the European College of Sport Science, Dublin, Irland},
  booktitle = {23rd Annual Congress of the European College of Sport Science, Dublin, Irland},
  year      = {2018},
  language  = {en}
}
@article{HeinkeKnickerAlbracht2018,
  author    = {Heinke, Lars N. and Knicker, Axel J. and Albracht, Kirsten},
  title     = {Evaluation of passively induced shoulder stretch reflex using an isokinetic dynamometer in male overhead athletes},
  series = {Isokinetics and Exercise Science},
  volume    = {26},
  journal   = {Isokinetics and Exercise Science},
  number    = {4},
  publisher = {IOS Press},
  address   = {Amsterdam},
  issn      = {1878-5913},
  doi       = {10.3233/IES-184111},
  pages     = {265 -- 274},
  year      = {2018},
  abstract  = {BACKGROUND: Muscle stretch reflexes are widely considered to beneficially influence joint stability and power generation in the lower limbs. While in the upper limbs and especially in the muscles surrounding the shoulder joint such evidence is lacking. OBJECTIVE: To quantify the electromyographical response in the muscles crossing the shoulder of specifically trained overhead athletes to an anterior perturbation force. METHODS: Twenty healthy male participants performed six sets of different external shoulder rotation stretches on an isokinetic dynamometer over a range of amplitudes and muscle pre-activation moment levels. All stretches were applied with a dynamometer acceleration of 10,000∘/s2 and a velocity of 150∘/s. Electromyographical response was measured via sEMG. RESULTS: Consistent reflexes were not observed in all experimental conditions. The reflex latencies revealed a significant muscle main effect (F (2,228) = 99.31, p< 0.001; η2= 0.466; f= 0.934) and a pre-activation main effect (F (1,228) = 142.21, p< 0.001; η2= 0.384; f= 1.418). The stretch reflex amplitude yielded a significant pre-activation main effect (F (1,222) = 470.373, p< 0.001; η2= 0.679; f= 1.454). CONCLUSION: Short latency muscle reflexes showed a tendency to an anterior to posterior muscle recruitment whereby the main internal rotator muscles of the shoulder revealed the most consistent results.},
  language  = {en}
}
@article{CapriMorsianiSantoroetal.2019,
  author    = {Capri, Miriam and Morsiani, Cristina and Santoro, Aurelia and Moriggi, Manuela and Conte, Maria and Martucci, Morena and Bellavista, Elena and Fabbri, Cristina and Giampieri, Enrico and Albracht, Kirsten and Fl{\"u}ck, Martin and Ruoss, Severin and Brocca, Lorenza and Canepari, Monica and Longa, Emanuela and Giulio, Irene Di and Bottinelli, Roberto and Cerretelli, Paolo and Salvioli, Stefano and Gelfi, Cecilia and Franceschi, Claudio and Narici, Marco and Rittweger, J{\"o}rn},
  title     = {Recovery from 6-month spaceflight at the International Space Station: muscle-related stress into a proinflammatory setting},
  series = {The FASEB journal : official publication of the Federation of American Societies for Experimental Biology},
  volume    = {33},
  journal   = {The FASEB journal : official publication of the Federation of American Societies for Experimental Biology},
  number    = {4},
  doi       = {10.1096/fj.201801625R},
  pages     = {5168 -- 5180},
  year      = {2019},
  language  = {en}
}
@article{QuittmannAbelAlbrachtetal.2019,
  author    = {Quittmann, Oliver J. and Abel, Thomas and Albracht, Kirsten and Str{\"u}der, Heiko K.},
  title     = {Reliability of muscular activation patterns and their alterations during incremental handcycling in able-bodied participants},
  series = {Sports Biomechanics},
  journal   = {Sports Biomechanics},
  number    = {Article in press},
  publisher = {Taylor \& Francis},
  address   = {London},
  issn      = {1752-6116},
  doi       = {10.1080/14763141.2019.1593496},
  year      = {2019},
  language  = {en}
}
@article{HeinkeKnickerAlbracht2020,
  author    = {Heinke, Lars N. and Knicker, Axel J. and Albracht, Kirsten},
  title     = {Increased shoulder muscle stretch reflex elicitability in supine subject posture},
  series = {Isokinetics and Exercise Science},
  volume    = {28},
  journal   = {Isokinetics and Exercise Science},
  number    = {2},
  publisher = {IOS Press},
  address   = {Amsterdam},
  issn      = {1878-5913},
  doi       = {10.3233/IES-192219},
  pages     = {139 -- 146},
  year      = {2020},
  abstract  = {BACKGROUND: Muscle stretch reflexes are widely used to examine neural muscle function. The knowledge of reflex response in muscles crossing the shoulder is limited. OBJECTIVE: To quantify reflex modulation according to various subject postures and different procedures of muscle pre-activation steering. METHODS: Thirteen healthy male participants performed two sets of external shoulder rotation stretches in various positions and with different procedures of muscle pre-activation steering on an isokinetic dynamometer over a range of two different pre-activation levels. All stretches were applied with a dynamometer acceleration of 104∘/s2 and a velocity of 150∘/s. Electromyographical response was measured via sEMG. RESULTS: Consistent reflexive response was observed in all tested muscles in all experimental conditions. The reflex elicitation rate revealed a significant muscle main effect (F (5,288) = 2.358, ρ= 0.040; η2= 0.039; f= 0.637) and a significant test condition main effect (F (1,288) = 5.884, ρ= 0.016; η2= 0.020; f= 0.143). Reflex latency revealed a significant muscle pre-activation level main effect (F (1,274) = 5.008, ρ= 0.026; η2= 0.018; f= 0.469). CONCLUSION: Muscular reflexive response was more consistent in the primary internal rotators of the shoulder. Supine posture in combination with visual feedback of muscle pre-activation level enhanced the reflex elicitation rate.},
  language  = {en}
}
@article{HeinkeKnickerAlbracht2021,
  author    = {Heinke, Lars N. and Knicker, Axel J. and Albracht, Kirsten},
  title     = {Test-retest reliability of the internal shoulder rotator muscles' stretch reflex in healthy men},
  series = {Journal of Electromyography and Kinesiology},
  volume    = {62},
  journal   = {Journal of Electromyography and Kinesiology},
  number    = {Article 102611},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1050-6411},
  doi       = {10.1016/j.jelekin.2021.102611},
  year      = {2021},
  abstract  = {Until now the reproducibility of the short latency stretch reflex of the internal rotator muscles of the glenohumeral joint has not been identified. Twenty-three healthy male participants performed three sets of external shoulder rotation stretches with various pre-activation levels on two different dates of measurement to assess test-retest reliability. All stretches were applied with a dynamometer acceleration of 104°/s2 and a velocity of 150°/s. Electromyographical response was measured via surface EMG. Reflex latencies showed a pre-activation effect (ƞ2 = 0,355). ICC ranged from 0,735 to 0,909 indicating an overall "good" relative reliability. SRD 95\% lay between ±7,0 to ±12,3 ms.. The reflex gain showed overall poor test-retest reproducibility. The chosen methodological approach presented a suitable test protocol for shoulder muscles stretch reflex latency evaluation. A proof-of-concept study to validate the presented methodical approach in shoulder involvement including subjects with clinically relevant conditions is recommended.},
  language  = {en}
}
@article{LiphardtFernandezGonzaloAlbrachtetal.2023,
  author    = {Liphardt, Anna-Maria and Fernandez-Gonzalo, Rodrigo and Albracht, Kirsten and Rittweger, J{\"o}rn and Vico, Laurence},
  title     = {Musculoskeletal research in human space flight - unmet needs for the success of crewed deep space exploration},
  series = {npj Microgravity},
  volume    = {9},
  journal   = {npj Microgravity},
  number    = {Article number: 9},
  publisher = {Springer Nature},
  issn      = {2373-8065},
  doi       = {10.1038/s41526-023-00258-3},
  pages     = {1 -- 9},
  year      = {2023},
  abstract  = {Based on the European Space Agency (ESA) Science in Space Environment (SciSpacE) community White Paper "Human Physiology - Musculoskeletal system", this perspective highlights unmet needs and suggests new avenues for future studies in musculoskeletal research to enable crewed exploration missions. The musculoskeletal system is essential for sustaining physical function and energy metabolism, and the maintenance of health during exploration missions, and consequently mission success, will be tightly linked to musculoskeletal function. Data collection from current space missions from pre-, during-, and post-flight periods would provide important information to understand and ultimately offset musculoskeletal alterations during long-term spaceflight. In addition, understanding the kinetics of the different components of the musculoskeletal system in parallel with a detailed description of the molecular mechanisms driving these alterations appears to be the best approach to address potential musculoskeletal problems that future exploratory-mission crew will face. These research efforts should be accompanied by technical advances in molecular and phenotypic monitoring tools to provide in-flight real-time feedback.},
  language  = {en}
}
@article{SchoenrockMuckeltHastermannetal.2024,
  author    = {Schoenrock, Britt and Muckelt, Paul E. and Hastermann, Maria and Albracht, Kirsten and MacGregor, Robert and Martin, David and Gunga, Hans-Christian and Salanova, Michele and Stokes, Maria J. and Warner, Martin B. and Blottner, Dieter},
  title     = {Muscle stiffness indicating mission crew health in space},
  series = {Scientific Reports},
  volume    = {14},
  journal   = {Scientific Reports},
  number    = {Article number: 4196},
  publisher = {Springer Nature},
  address   = {London},
  issn      = {2045-2322},
  doi       = {10.1038/s41598-024-54759-6},
  pages     = {13 Seiten},
  year      = {2024},
  abstract  = {Muscle function is compromised by gravitational unloading in space affecting overall musculoskeletal health. Astronauts perform daily exercise programmes to mitigate these effects but knowing which muscles to target would optimise effectiveness. Accurate inflight assessment to inform exercise programmes is critical due to lack of technologies suitable for spaceflight. Changes in mechanical properties indicate muscle health status and can be measured rapidly and non-invasively using novel technology. A hand-held MyotonPRO device enabled monitoring of muscle health for the first time in spaceflight (> 180 days). Greater/maintained stiffness indicated countermeasures were effective. Tissue stiffness was preserved in the majority of muscles (neck, shoulder, back, thigh) but Tibialis Anterior (foot lever muscle) stiffness decreased inflight vs. preflight (p < 0.0001; mean difference 149 N/m) in all 12 crewmembers. The calf muscles showed opposing effects, Gastrocnemius increasing in stiffness Soleus decreasing. Selective stiffness decrements indicate lack of preservation despite daily inflight countermeasures. This calls for more targeted exercises for lower leg muscles with vital roles as ankle joint stabilizers and in gait. Muscle stiffness is a digital biomarker for risk monitoring during future planetary explorations (Moon, Mars), for healthcare management in challenging environments or clinical disorders in people on Earth, to enable effective tailored exercise programmes.},
  language  = {en}
}
@article{QuittmannMeskemperAlbrachtetal.2020,
  author    = {Quittmann, Oliver J. and Meskemper, Joshua and Albracht, Kirsten and Abel, Thomas and Foitschik, Tina and Str{\"u}der, Heiko K.},
  title     = {Normalising surface EMG of ten upper-extremity muscles in handcycling: Manual resistance vs. sport-specific MVICs},
  series = {Journal of Electromyography and Kinesiology},
  volume    = {51},
  journal   = {Journal of Electromyography and Kinesiology},
  number    = {Article 102402},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {1050-6411},
  doi       = {10.1016/j.jelekin.2020.102402},
  year      = {2020},
  abstract  = {Muscular activity in terms of surface electromyography (sEMG) is usually normalised to maximal voluntary isometric contractions (MVICs). This study aims to compare two different MVIC-modes in handcycling and examine the effect of moving average window-size. Twelve able-bodied male competitive triathletes performed ten MVICs against manual resistance and four sport-specific trials against fixed cranks. sEMG of ten muscles [M. trapezius (TD); M. pectoralis major (PM); M. deltoideus, Pars clavicularis (DA); M. deltoideus, Pars spinalis (DP); M. biceps brachii (BB); M. triceps brachii (TB); forearm flexors (FC); forearm extensors (EC); M. latissimus dorsi (LD) and M. rectus abdominis (RA)] was recorded and filtered using moving average window-sizes of 150, 200, 250 and 300 ms. Sport-specific MVICs were higher compared to manual resistance for TB, DA, DP and LD, whereas FC, TD, BB and RA demonstrated lower values. PM and EC demonstrated no significant difference between MVIC-modes. Moving average window-size had no effect on MVIC outcomes. MVIC-mode should be taken into account when normalised sEMG data are illustrated in handcycling. Sport-specific MVICs seem to be suitable for some muscles (TB, DA, DP and LD), but should be augmented by MVICs against manual/mechanical resistance for FC, TD, BB and RA.},
  language  = {en}
}
@article{QuittmannAbelAlbrachtetal.2020,
  author    = {Quittmann, Oliver J. and Abel, Thomas and Albracht, Kirsten and Meskemper, Joshua and Foitschik, Tina and Str{\"u}der, Heiko K.},
  title     = {Biomechanics of handcycling propulsion in a 30-min continuous load test at lactate threshold: Kinetics, kinematics, and muscular activity in able-bodied participants},
  series = {European Journal of Applied Physiology},
  journal   = {European Journal of Applied Physiology},
  number    = {120},
  publisher = {Springer},
  address   = {Heidelberg},
  issn      = {1439-6327},
  doi       = {10.1007/s00421-020-04373-x},
  pages     = {1403 -- 1415},
  year      = {2020},
  abstract  = {Purpose This study aims to investigate the biomechanics of handcycling during a continuous load trial (CLT) to assess the mechanisms underlying fatigue in upper body exercise. Methods Twelve able-bodied triathletes performed a 30-min CLT at a power output corresponding to lactate threshold in a racing recumbent handcycle mounted on a stationary ergometer. During the CLT, ratings of perceived exertion (RPE), tangential crank kinetics, 3D joint kinematics, and muscular activity of ten muscles of the upper extremity and trunk were examined using motion capturing and surface electromyography. Results During the CLT, spontaneously chosen cadence and RPE increased, whereas crank torque decreased. Rotational work was higher during the pull phase. Peripheral RPE was higher compared to central RPE. Joint range of motion decreased for elbow-flexion and radial-duction. Integrated EMG (iEMG) increased in the forearm flexors, forearm extensors, and M. deltoideus (Pars spinalis). An earlier onset of activation was found for M. deltoideus (Pars clavicularis), M. pectoralis major, M. rectus abdominis, M. biceps brachii, and the forearm flexors. Conclusion Fatigue-related alterations seem to apply analogously in handcycling and cycling. The most distal muscles are responsible for force transmission on the cranks and might thus suffer most from neuromuscular fatigue. The findings indicate that peripheral fatigue (at similar lactate values) is higher in handcycling compared to leg cycling, at least for inexperienced participants. An increase in cadence might delay peripheral fatigue by a reduced vascular occlusion. We assume that the gap between peripheral and central fatigue can be reduced by sport-specific endurance training.},
  language  = {en}
}
@inproceedings{PohleFroehlichDalitzRichteretal.2020,
  author    = {Pohle-Fr{\"o}hlich, Regina and Dalitz, Christoph and Richter, Charlotte and Hahnen, Tobias and St{\"a}udle, Benjamin and Albracht, Kirsten},
  title     = {Estimation of muscle fascicle orientation in ultrasonic images},
  series = {VISIGRAPP 2020 - Proceedings of the 15th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, 5},
  booktitle = {VISIGRAPP 2020 - Proceedings of the 15th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, 5},
  pages     = {79 -- 86},
  year      = {2020},
  language  = {en}
}
@article{WerkhausenCroninAlbrachtetal.2019,
  author    = {Werkhausen, Amelie and Cronin, Neil J. and Albracht, Kirsten and Bojsen-M{\o}ller, Jens and Seynnes, Olivier R.},
  title     = {Distinct muscle-tendon interaction during running at different speeds and in different loading conditions},
  series = {Journal of Applied Physiology},
  volume    = {127},
  journal   = {Journal of Applied Physiology},
  number    = {1},
  issn      = {1522-1601},
  doi       = {10.1152/japplphysiol.00710.2018},
  pages     = {246 -- 253},
  year      = {2019},
  language  = {en}
}
@article{WaldvogelRitzmannFreyleretal.2021,
  author    = {Waldvogel, Janice and Ritzmann, Ramona and Freyler, Kathrin and Helm, Michael and Monti, Elena and Albracht, Kirsten and St{\"a}udle, Benjamin and Gollhofer, Albert and Narici, Marco},
  title     = {The Anticipation of Gravity in Human Ballistic Movement},
  series = {Frontiers in Physiology},
  journal   = {Frontiers in Physiology},
  publisher = {Frontiers},
  address   = {Lausanne},
  issn      = {1664-042X},
  doi       = {10.3389/fphys.2021.614060},
  year      = {2021},
  abstract  = {Stretch-shortening type actions are characterized by lengthening of the pre-activated muscle-tendon unit (MTU) in the eccentric phase immediately followed by muscle shortening. Under 1 g, pre-activity before and muscle activity after ground contact, scale muscle stiffness, which is crucial for the recoil properties of the MTU in the subsequent push-off. This study aimed to examine the neuro-mechanical coupling of the stretch-shortening cycle in response to gravity levels ranging from 0.1 to 2 g. During parabolic flights, 17 subjects performed drop jumps while electromyography (EMG) of the lower limb muscles was combined with ultrasound images of the gastrocnemius medialis, 2D kinematics and kinetics to depict changes in energy management and performance. Neuro-mechanical coupling in 1 g was characterized by high magnitudes of pre-activity and eccentric muscle activity allowing an isometric muscle behavior during ground contact. EMG during pre-activity and the concentric phase systematically increased from 0.1 to 1 g. Below 1 g the EMG in the eccentric phase was diminished, leading to muscle lengthening and reduced MTU stretches. Kinetic energy at take-off and performance were decreased compared to 1 g. Above 1 g, reduced EMG in the eccentric phase was accompanied by large MTU and muscle stretch, increased joint flexion amplitudes, energy loss and reduced performance. The energy outcome function established by linear mixed model reveals that the central nervous system regulates the extensor muscles phase- and load-specifically. In conclusion, neuro-mechanical coupling appears to be optimized in 1 g. Below 1 g, the energy outcome is compromised by reduced muscle stiffness. Above 1 g, loading progressively induces muscle lengthening, thus facilitating energy dissipation.},
  language  = {en}
}
@article{MoratFaudeHanssenetal.2020,
  author    = {Morat, Mareike and Faude, Oliver and Hanssen, Henner and Ludyga, Sebastian and Zacher, Jonas and Eibl, Angi and Albracht, Kirsten and Donath, Lars},
  title     = {Agility Training to Integratively Promote Neuromuscular, Cognitive, Cardiovascular and Psychosocial Function in Healthy Older Adults: A Study Protocol of a One-Year Randomized-Controlled Trial},
  series = {International Journal of Environmental Research and Public Health},
  volume    = {17},
  journal   = {International Journal of Environmental Research and Public Health},
  number    = {6},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1660-4601},
  doi       = {10.3390/ijerph17061853},
  pages     = {1 -- 14},
  year      = {2020},
  abstract  = {Exercise training effectively mitigates aging-induced health and fitness impairments. Traditional training recommendations for the elderly focus separately on relevant physiological fitness domains, such as balance, flexibility, strength and endurance. Thus, a more holistic and functional training framework is needed. The proposed agility training concept integratively tackles spatial orientation, stop and go, balance and strength. The presented protocol aims at introducing a two-armed, one-year randomized controlled trial, evaluating the effects of this concept on neuromuscular, cardiovascular, cognitive and psychosocial health outcomes in healthy older adults. Eighty-five participants were enrolled in this ongoing trial. Seventy-nine participants completed baseline testing and were block-randomized to the agility training group or the inactive control group. All participants undergo pre- and post-testing with interim assessment after six months. The intervention group currently receives supervised, group-based agility training twice a week over one year, with progressively demanding perceptual, cognitive and physical exercises. Knee extension strength, reactive balance, dual task gait speed and the Agility Challenge for the Elderly (ACE) serve as primary endpoints and neuromuscular, cognitive, cardiovascular, and psychosocial meassures serve as surrogate secondary outcomes. Our protocol promotes a comprehensive exercise training concept for older adults, that might facilitate stakeholders in health and exercise to stimulate relevant health outcomes without relying on excessively time-consuming physical activity recommendations.},
  language  = {en}
}
@misc{BlottnerHastermannMuckeltetal.2019,
  author    = {Blottner, Dieter and Hastermann, Maria and Muckelt, Paul and Albracht, Kirsten and Schoenrock, Britt and Salanova, Michele and Warner, Martin and Gunga, Hans-Christian and Stokes, Maria},
  title     = {MYOTONES - Inflight muscle health status monitoring during long-duration space missions onboard the International Space Station: a single case study},
  series = {IAC Papers Archive},
  journal   = {IAC Papers Archive},
  publisher = {Pergamon},
  address   = {Oxford},
  issn      = {00741795},
  pages     = {2 Seiten},
  year      = {2019},
  abstract  = {The MYOTONES experiment is the first to monitor changes in the basic biomechanical properties (tone, elasticity and stiffness) of the resting human myofascial system due to microgravity with a oninvasive, portable device on board the ISS. The MyotonPRO device applies several brief mechanical stimuli to the surface of the skin, and the natural oscillation signals of the tissue beneath are detected and computed by the MyotonPRO. Thus, an objective, quick and easy determination of the state of the underlying tissue is possible. Two preflight, four inflight and four post flight measurements were performed on a male astronaut using the same 10 measurement points (MP) for each session. MPs were located on the plantar fascia, Achilles tendon, M. soleus, M. gastrocnemius, M. multifidus, M. splenius capitis, M. deltoideus anterior, M. rectus femoris, infrapatellar tendon, M. tibialis anterior. Subcutaneous tissues thickness above the MPs was measured using ultrasound imaging. Magnetic resonance images (MRI) of lower limb muscles and functional tests were also performed pre- and postflight. Our first measurements on board the ISS confirmed increased tone and stiffness of the lumbar multifidus muscle, an important trunk stabilizer, dysfunction of which is known to be associated with back pain. Furthermore, reduced tone and stiffness of Achilles tendon and plantar fascia were observed inflight vs. preflight, confirming previous findings from terrestrial analog studies and parabolic flights. Unexpectedly, the deltoid showed negative inflight changes in tone and stiffness, and increased elasticity, suggesting a potential risk of muscle atrophy in longer spaceflight that should be addressed by adequate inflight countermeasure protocols. Most values from limb and back MPS showed deflected patterns (in either directions) from inflight shortly after the re-entry phase on the landing day and one week later. Most parameter values then normalized to baseline after 3 weeks likely due to 1G re-adaptation and possible outcome of the reconditioning protocol. No major changes in subcutaneous tissues thickness above the MPs were found inflight vs preflight, suggesting no bias (i.e., fluid shift, extreme tissue thickening or loss). Pre- and postflight MRI and functional tests showed negligible changes in calf muscle size, power and force, which is likely due to training effects from current inflight exercise protocols. The MYOTONES experiment is currently ongoing to collect data from further crew members. The potential impact of this research is to better understand the effects of microgravity and countermeasures over the time course of an ISS mission cycle. This will enable exercise countermeasures to be tailored},
  language  = {en}
}
@article{WerkhausenCroninAlbrachtetal.2019,
  author    = {Werkhausen, Amelie and Cronin, Neil J. and Albracht, Kirsten and Paulsen, G{\o}ran and Larsen, Askild V. and Bojsen-M{\o}ller, Jens and Seynnes, Olivier R.},
  title     = {Training-induced increase in Achilles tendon stiffness affects tendon strain pattern during running},
  series = {PeerJ},
  journal   = {PeerJ},
  publisher = {Peer},
  address   = {London},
  issn      = {21678359},
  doi       = {10.7717/peerj.6764},
  pages     = {18 Seiten},
  year      = {2019},
  abstract  = {Background During the stance phase of running, the elasticity of the Achilles tendon enables the utilisation of elastic energy and allows beneficial contractile conditions for the triceps surae muscles. However, the effect of changes in tendon mechanical properties induced by chronic loading is still poorly understood. We tested the hypothesis that a training-induced increase in Achilles tendon stiffness would result in reduced tendon strain during the stance phase of running, which would reduce fascicle strains in the triceps surae muscles, particularly in the mono-articular soleus. Methods Eleven subjects were assigned to a training group performing isometric singleleg plantarflexion contractions three times per week for ten weeks, and another ten subjects formed a control group. Before and after the training period, Achilles tendon stiffness was estimated, and muscle-tendon mechanics were assessed during running at preferred speed using ultrasonography, kinematics and kinetics. Results Achilles tendon stiffness increased by 18\% (P <0:01) in the training group, but the associated reduction in strain seen during isometric contractions was not statistically significant. Tendon elongation during the stance phase of running was similar after training, but tendon recoil was reduced by 30\% (P <0:01), while estimated tendon force remained unchanged. Neither gastrocnemius medialis nor soleus fascicle shortening during stance was affected by training. Discussion These results show that a training-induced increase in Achilles tendon stiffness altered tendon behaviour during running. Despite training-induced changes in tendon mechanical properties and recoil behaviour, the data suggest that fascicle shortening patterns were preserved for the running speed that we examined. The asymmetrical changes in tendon strain patterns supports the notion that simple inseries models do not fully explain the mechanical output of the muscle-tendon unit during a complex task like running.},
  language  = {en}
}
@article{KetelhutGoellBraunsteinetal.2018,
  author    = {Ketelhut, Maike and G{\"o}ll, Fabian and Braunstein, Bj{\"o}rn and Albracht, Kirsten and Abel, Dirk},
  title     = {Comparison of different training algorithms for the leg extension training with an industrial robot},
  series = {Current Directions in Biomedical Engineering},
  volume    = {4},
  journal   = {Current Directions in Biomedical Engineering},
  number    = {1},
  publisher = {De Gruyter},
  address   = {Berlin},
  issn      = {2364-5504},
  doi       = {10.1515/cdbme-2018-0005},
  pages     = {17 -- 20},
  year      = {2018},
  abstract  = {In the past, different training scenarios have been developed and implemented on robotic research platforms, but no systematic analysis and comparison have been done so far. This paper deals with the comparison of an isokinematic (motion with constant velocity) and an isotonic (motion against constant weight) training algorithm. Both algorithms are designed for a robotic research platform consisting of a 3D force plate and a high payload industrial robot, which allows leg extension training with arbitrary six-dimensional motion trajectories. In the isokinematic as well as the isotonic training algorithm, individual paths are defined i n C artesian s pace by sufficient s upport p oses. I n t he i sotonic t raining s cenario, the trajectory is adapted to the measured force as the robot should only move along the trajectory as long as the force applied by the user exceeds a minimum threshold. In the isotonic training scenario however, the robot's acceleration is a function of the force applied by the user. To validate these findings, a simulative experiment with a simple linear trajectory is performed. For this purpose, the same force path is applied in both training scenarios. The results illustrate that the algorithms differ in the force dependent trajectory adaption.},
  language  = {en}
}
@article{WerkhausenAlbrachtCroninetal.2018,
  author    = {Werkhausen, Amelie and Albracht, Kirsten and Cronin, Neil J and Paulsen, G{\o}ran and Bojsen-M{\o}ller, Jens and Seynnes, Olivier R},
  title     = {Effect of training-induced changes in achilles tendon stiffness on muscle-tendon behavior during landing},
  series = {Frontiers in physiology},
  journal   = {Frontiers in physiology},
  number    = {9},
  publisher = {Frontiers Research Foundation},
  address   = {Lausanne},
  issn      = {1664-042X},
  doi       = {10.3389/fphys.2018.00794},
  pages     = {11 Seiten},
  year      = {2018},
  abstract  = {During rapid deceleration of the body, tendons buffer part of the elongation of the muscle-tendon unit (MTU), enabling safe energy dissipation via eccentric muscle contraction. Yet, the influence of changes in tendon stiffness within the physiological range upon these lengthening contractions is unknown. This study aimed to examine the effect of training-induced stiffening of the Achilles tendon on triceps surae muscle-tendon behavior during a landing task. Twenty-one male subjects were assigned to either a 10-week resistance-training program consisting of single-leg isometric plantarflexion (n = 11) or to a non-training control group (n = 10). Before and after the training period, plantarflexion force, peak Achilles tendon strain and stiffness were measured during isometric contractions, using a combination of dynamometry, ultrasound and kinematics data. Additionally, testing included a step-landing task, during which joint mechanics and lengths of gastrocnemius and soleus fascicles, Achilles tendon, and MTU were determined using synchronized ultrasound, kinematics and kinetics data collection. After training, plantarflexion strength and Achilles tendon stiffness increased (15 and 18\%, respectively), and tendon strain during landing remained similar. Likewise, lengthening and negative work produced by the gastrocnemius MTU did not change detectably. However, in the training group, gastrocnemius fascicle length was offset (8\%) to a longer length at touch down and, surprisingly, fascicle lengthening and velocity were reduced by 27 and 21\%, respectively. These changes were not observed for soleus fascicles when accounting for variation in task execution between tests. These results indicate that a training-induced increase in tendon stiffness does not noticeably affect the buffering action of the tendon when the MTU is rapidly stretched. Reductions in gastrocnemius fascicle lengthening and lengthening velocity during landing occurred independently from tendon strain. Future studies are required to provide insight into the mechanisms underpinning these observations and their influence on energy dissipation.},
  language  = {en}
}
@article{YangKriechbaumerAlbrachtetal.2014,
  author    = {Yang, Peng-Fei and Kriechbaumer, Andreas and Albracht, Kirsten and Sanno, Maximilian and Ganse, Bergita and Koy, Timmo and Shang, Peng and br{\"u}ggemann, Gert-Peter and M{\"u}ller, Lars Peter and Rittweger, J{\"o}rn},
  title     = {A novel optical approach for assessing in vivo bone segment deformation and its application in muscle-bone relationship studies in humans},
  series = {Journal of Orthopaedic Translation},
  volume    = {2},
  journal   = {Journal of Orthopaedic Translation},
  number    = {4},
  publisher = {Elsevier},
  address   = {Singapore},
  issn      = {2214-0328},
  doi       = {10.1016/j.jot.2014.07.078},
  pages     = {238 -- 238},
  year      = {2014},
  language  = {en}
}